The present invention relates to a vehicle protection system and device which controls and prevents abnormal and/or unauthorised functioning of the motor vehicle""s parts by controlling the battery power supply transmission directly from the battery and fuel tank fuel supply directly from the fuel tank.
Prior art vehicle anti-theft protection systems use various means to immobilise a vehicle. These usually involve cutting off power supply to the vehicle parts or preventing fuel supply when the car is parked. Alternatively, the vehicle""s parking brakes may be activated. A control device is usually placed between the main relay and the engine control unit. Upon receipt of a correct enabling code, the control device will reverse the immobilisation device. The disadvantage of such systems thus far is that such an apparatus can be tampered with by re-wiring or changing of part of the wiring, by for example, connecting the battery to the engine control unit and by-passing the control device. Thus their reliability is reduced.
In U.S. Pat. No. 5,559,493 there is described an automobile anti-theft device which is connected to the electrical system and the fuel line of the system. This device includes an anti-theft system designed to prevent opening of a pre-existing valve in the fuel supply line, unless the correct code is entered. However, this anti-theft device can be defeated by providing an electrical connection direct from the automobile battery to the pre-existing valve.
The objective of the system of the present invention is to improve upon devices which only control and prevent abnormal and/or unauthorised functioning based upon the power supply, so as to make the device more comprehensive and reliable.
Broadly, in one aspect, the present invention involves disabling the fuel supply from the fuel tank to the engine and also disabling the supply of electrical power from the vehicle battery, unless the correct activation code is received. The operator could enter the activation code in a number of ways, for example, by a key or a keypad.
According to one aspect of the invention there is provided an anti-theft device for a vehicle, comprising: a valve means operable to open and close a fuel supply line of a vehicle thereby respectively preventing and permitting fuel flow through said fuel supply line, the valve means opening in response to an electrical current supply and closing in response to the lack of an electrical current supply; and a control means for selectively enabling and disabling said electrical current supply to the valve means, the control means enabling said electrical current supply in response to receiving a specific encoded signal, and disabling said electrical current supply at other times.
Preferably, the anti-theft device further comprises a fuel supply control line adapted to be disposed in fuel supply line of a vehicle, and the valve means is arranged to control fuel flow through said fuel supply control line.
Desirably, the control means enables said electrical current supply in response to a specific start-up encoded signal. In a preferred embodiment, the control means comprises a power control unit adapted to enable the electrical current supply to the valve means in response to an activation signal; and an encoded signal control unit adapted to generate said activation signal and to transmit the activation signal to the power control unit in response to receiving said specific start-up encoded signal.
It is also desirable that the control means disables said electrical current supply in response to a specific shut-down encoded signal. In a preferred embodiment, the power control unit is adapted to disable the electrical current supply to the valve means in response to a deactivation signal; and the encoded signal control unit is adapted to generate said deactivation signal and to transmit the deactivation signal to the power control unit in response to receiving said specific shut-down encoded signal.
Preferably, the encoded signal control unit includes a receiver for receiving an encoded signal, storage means for storing a representation of said specific start-up encoded signal, a comparator for comparing a received signal with the representation of the specific start-up encoded signal in the storage means, and a signal generator for generating the activation signal when the comparator has determined that the received encoded signal is identical to the representation of the specific start-up encoded signal.
The storage means may also store a representation of said specific shut-down encoded signal, and the comparator may also compare the received signal with the representation of the specific shut-down encoded signal in the storage means, and the signal generator may generate the deactivation signal when the comparator has determined that the received encoded signal is identical to the representation of the specific shut-down encoded signal.
The source of electrical power In the vehicle will usually be a vehicle battery, in which case, the control means may be adapted to be placed in electrical contact with the vehicle battery, whereby the electrical current supply is provided by the vehicle battery.
In a preferred embodiment, the control means is adapted to be placed in electrical communication with at (east one other electrically operated component of the vehicle, whereby the control means can control the electrical supply to the or each other component. The other component may be, for example, an engine control unit or an indicator light.
It is preferred-that-the anti-theft device further comprises a tamper-proof using within which the valve means and the control means are housed.
The anti-theft device may further comprise a start-up unit for generating and transmitting the specific encoded signal The start-up unit may include a transponder for generating and transmitting the specific encoded signal in the form of a radio wave. The start-up unit may be activated by any suitable means, such as a mechanical key or by the entry of a code into a keypad, and so on.
The valve means may be any suitable form of valve. A conventional magnetic valve, such as solenoid valve is usually convenient.
According to another aspect of the invention there is provided a vehicle incorporating an anti-theft device as described above. The vehicle would typically include a battery, a fuel tank and an engine, and the anti-theft device would be disposed in the fuel line from the fuel tank to the engine, whereby the anti-theft device could control the fuel supply to the engine. The anti-theft device would also control the electrical supply from the vehicle battery to the valve means of the anti-theft device, and preferably would additionally control the electrical supply from the vehicle battery to other components of the vehicle, such as an engine management system and/or indicator lights.
The anti-theft device according to the invention is particularly suitable for use with automobiles. The anti-theft device may be pre-installed in the vehicle, or may be supplied separately for retrofitting to the vehicle.
According to another aspect of the invention there is provided a method of preventing unauthorised use of a vehicle comprising installing a valve means in the fuel supply line of the vehicle between a fuel tank and an engine of the vehicle, the valve means being operable, by an electrical current from a battery of the vehicle, to permit fuel flow from the fuel tank to the engine; and controlling the supply of electrical current from the battery to the valve means such that the supply is only provided in response to a specific encoded signal, whereby fuel can be supplied to the engine only in response to receipt of said specific encoded signal.
Preferably, the electrical supply to at least one other electrical component of the vehicle is also controlled such that the battery is placed in electrical contact with the or each other component only in response to receipt of said specific encoded signal.
Broadly, in another aspect, the invention involves inserting an anti-theft device into a fuel supply line of a vehicle, the anti-theft device comprising a housing containing a valve to prevent fuel flow through the device, unless the correct activation code Is received.
According to another aspect of the invention there is provided an anti-theft device for a vehicle, comprising; a housing; a fuel supply control line disposed in the housing and adapted to be disposed in a fuel supply line of a vehicle; a valve means disposed in the housing, the valve means being operable to open and close the fuel supply control line thereby respectively permitting and preventing fuel flow through said fuel supply control line; and a control means disposed in the housing, the control means selectively opening and closing the valve means in response to receiving a specific encoded signal.
Preferably, the valve means opens in response to an electrical current supply and closes in response to the lack of said electrical current supply, and the control means selectively enables and disables said electrical current supply to the valve means, the control means enabling said electrical current supply in response to receiving said specific encoded signal, and disabling said electrical current supply at other times.
Preferably, the housing Is substantially tamper proof. To this end, the housing is preferably made of a strong, durable material that is not easily broken. A number of plastics and metallic materials would be suitable.
The invention is now described in more detail in relation to the preferred embodiment of the invention, with reference to the accompanying drawings.